char pointers in C

Rishi Kumar · 05-23-2008, 02:54 AM

thanx Elysia...

i dont get any error with fgets...
i use dev c++ with gcc compiler...
but i get a warning: "passing arg 1 of `fgets' from incompatible pointer type"... y???

39ster · 05-23-2008, 02:55 AM

What's so bad about casting malloc in C? Wouldnt it be better because it will be easier to transfer your C code to C++?

stevesmithx · 05-23-2008, 02:56 AM

Thank you laserlight.
I had saved it as .C
For .c it works.
And I thought extensions are not case sensitive.
Thanks all

**laserlight** · 05-23-2008, 02:58 AM

Quote:

What's so bad about casting malloc in C? Wouldnt it be better because it will be easier to transfer your C code to C++?

read casting malloc.

Elysia · 05-23-2008, 02:59 AM

Quote:

Originally Posted by Rishi Kumar

thanx Elysia...

i dont get any error with fgets...
i use dev c++ with gcc compiler...
but i get a warning: "passing arg 1 of `fgets' from incompatible pointer type"... y???

It means that you are trying to pass an argument to a function that expects a pointer of a certain type, but you are passing another type of pointer.
If we could see the fgets code, maybe we could help.

Example:

Code:

int x;
fgets(&x, 1, 1, f); /* passing arg 1 of `fgets' from incompatible pointer type */

(fgets is expecting char*, not int*)

Quote:

Originally Posted by 39ster

What's so bad about casting malloc in C?

Because of implicit function calls are masked (in case you forgot to include the header where malloc's prototype resides). See the FAQ for more details.

Quote:

Originally Posted by 39ster

Wouldnt it be better because it will be easier to transfer your C code to C++?

I certainly do agree with you there. I like to call it C++/C

C code compiled with C++.
But we can't force anyone.

Rishi Kumar · 05-23-2008, 03:03 AM

Code:

#include<stdio.h>
#include<conio.h>
main()
{
char *s[10];
fgets(s, 10, stdin);
printf("%s",s);
getch();
}

it shows a warning...
" passing arg 1 of `fgets' from incompatible pointer type "

i accept only char* as input...

**laserlight** · 05-23-2008, 03:06 AM

In your new code example, s is an array of 10 char pointers. What you want is:

Code:

#include<stdio.h>

int main()
{
    char s[10];
    fgets(s, 10, stdin);
    printf("%s",s);
    return 0;
}

Elysia · 05-23-2008, 03:07 AM

Try reading the link for implicit main and get rid of it.
The problem is

Code:

char* s[10];

Which creates an array of 10 char pointers.
Thus passing this to fgets will result in char**.
Futher, the array has no allocates storage so you'd get a crash immediately.

And it's better to use getchar() instead of getch() (it's non-standard).

05-23-2008, 02:54 AM	#16
Rishi Kumar Registered User Join Date: May 2008 Posts: 6	thanx Elysia... i dont get any error with fgets... i use dev c++ with gcc compiler... but i get a warning: "passing arg 1 of `fgets' from incompatible pointer type"... y???
Rishi Kumar is offline

05-23-2008, 02:55 AM	#17
39ster Registered User Join Date: Apr 2007 Location: Sydney, Australia Posts: 217	What's so bad about casting malloc in C? Wouldnt it be better because it will be easier to transfer your C code to C++?
39ster is offline

05-23-2008, 02:56 AM	#18
stevesmithx and the hat of copycat Join Date: Sep 2007 Posts: 417	Thank you laserlight. I had saved it as .C For .c it works. And I thought extensions are not case sensitive. Thanks all __________________ Not everything that can be counted counts, and not everything that counts can be counted - Albert Einstein. No programming language is perfect. There is not even a single best language; there are only languages well suited or perhaps poorly suited for particular purposes. - Herbert Mayer
stevesmithx is offline

05-23-2008, 03:03 AM	#21
Rishi Kumar Registered User Join Date: May 2008 Posts: 6	Code: #include<stdio.h> #include<conio.h> main() { char s[10]; fgets(s, 10, stdin); printf("%s",s); getch(); } it shows a warning... " passing arg 1 of `fgets' from incompatible pointer type " i accept only char as input...
Rishi Kumar is offline

05-23-2008, 03:06 AM	#22
laserlight C++ Witch Join Date: Oct 2003 Location: Singapore Posts: 11,362	In your new code example, s is an array of 10 char pointers. What you want is: Code: #include<stdio.h> int main() { char s[10]; fgets(s, 10, stdin); printf("%s",s); return 0; } __________________ C + C++ Compiler: MinGW port of GCC Build + Version Control System: SCons + Bazaar Look up a C/C++ Reference and learn How To Ask Questions The Smart Way
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